Dissemination of Exhaled Plumes During the Use of Nasal Cannulae and Simple Oxygen Masks by Healthy Volunteers -- Potential Issues for Low Energy Healthcare Institutions PDF

Background: In low energy buildings dedicated to healthcare, energy savings may be sought by reducing the numbers of air changes per hour(ACH), and the degree of negative pressure differentials maintained in isolation units. Oxygen masks worn by patients and connected to highflowoxygen supplies may be a potential source of infectious aerosols. This study investigates the plumes generated by the most commonly usedrespiratory assist devices, nasal cannulae and simple oxygen masks, at different oxygen flow rates in healthy volunteers.Methods: A shadowgraph imaging system was used to visualize exhalation plumes generated by 11 healthy volunteers (5 females, 34.0+/-13.2;6 males, 28.7+/-6.9 years), wearing a nasal cannula or a simple oxygen mask at different oxygen supply rates. Maximum horizontaldissemination distances were measured for each flow rate, for each mask, for each volunteer, from digitized shadowgraph images.